CVD File

What are CVD files and how to open them

Are you having problems opening a CVD file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CVD files.

What is a CVD file?

CVD files have multiple uses, and Calamus Vector Document is one of them. Read more about the other uses further down the page.

Calamus Vector Document

Calamus Vector Document is a vector-graphics image file created by the desktop publishing program Calamus SL of invers-Software. It is used to save full vector pictures (scalable shapes, text, curves) that can be edited and placed into layouts, allowing resolution-independent artwork and precise control of elements in pages.

These documents are written (exported or saved) by Calamus SL when working with vector artwork, and later read by the same program for further editing, printing, or embedding inside larger page layouts. Calamus SL supports combining vector image files with text frames, raster images, typographic styles, and layout modules; a vector picture document typeset in Calamus SL can form part of a page layout or serve as a standalone illustration.

Files begin with a fixed ASCII header signature DMCCALAMUS CVD located at byte offset 0, which identifies the file as a Calamus Vector Document.

How to open CVD files

Important: Different programs may use files with the CVD file extension for different purposes, so unless you are sure which format your CVD file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested four different CVD openers which you will find listed below.

Last updated: September 19, 2026

All known file formats using extension .CVD

While Calamus Vector Document is a popular type of CVD-file, we know of 2 different uses of the .CVD file extension. Different software may use files with the same extension for different types of data.

Clam AntiVirus Database

Clam AntiVirus Database files store signature databases used by ClamAV, an open-source malware scanning toolkit. These files bundle one or more sets of detection rules that ClamAV uses to identify viruses, worms, trojans, and other malicious content. The purpose of this format is to allow ClamAV to verify the integrity of its signature databases (using digital signatures), to distribute updates efficiently, and to load many types of signature rules in a single archive.

These archives are created and distributed by ClamAV (maintained by Cisco Talos) and are downloaded using the FreshClam updater. They are used as the primary source of official virus definitions (common databases like main.cvd, daily.cvd, bytecode.cvd). End users typically receive these files via FreshClam; ClamAV then verifies the digital signature, uncompresses the internal archive (which is a tarball), and loads the individual signature rule files (such as .ndb, .ldb, *.hdb, etc.). Custom or local signature sets can be added alongside these official archives by placing appropriately named text-format signature files in the database directory.

Internally the archive begins with a 512-byte header composed of colon-separated ASCII fields that identify the archive type (marked with the string "ClamAV-VDB:" at the start), the build time, version, number of signatures, required functionality level, an MD5 checksum of the contained data, a digital signature (RSA signature over the checksum), the builder name, and the build timestamp in seconds. Following the header is a compressed tarball (often gzip or similar) that holds individual signature and metadata files.

These files are recognized by the ASCII header signature "ClamAV‐VDB:" at offset zero.

Various apps that use files with this extension

These apps are known to open certain types of CVD files. Remember, different programs may use CVD files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CVD file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.